The field of art to which this invention relates is medical devices, more specifically, medical devices and surgical procedures for performing anastomosis of hollow organs such as blood vessels.
Anastomoticsurgical procedures are common in the field of cardiac surgery. These procedures are conventionally used for repairing a damaged or diseased blood vessel. In a typical anastomotic procedure, a surgeon joins a first blood vessel to a second blood vessel and creates a passageway between the two blood vessels to provide for the communication of blood flow. For this kind of anastomosis, the surgeon typically uses specialized grasping tools to manipulate a tiny, curved needle attached to an extremely fine surgical filament (e.g., under 0.001 inch diameter) to suture the vessels together. The vessels may be joined end-to-end, end-to-side, or side-to-side. To facilitate healing of the joined vessels, the prevailing standard of care requires that the surgeon suture the inside surfaces of the first and second vessels together, intima to intima. The surgeon must take great care not to damage the intima of each vessel so that endothelial cells may form over the anastomosis without the formation of thrombus or other complications, thus improving the likelihood of a long term patency of the vessels. For life-saving procedures such as coronary artery bypass graft surgery (CABG), this is especially important. When performing a distal anastomosis in a conventional CABG procedure, the surgeon typically sutures an end-to-side anastomosis of a distal end of a graft vessel (such as a segment of saphenous vein harvested from the patient) to a side of a target vessel (the stenosed coronary artery). For a proximal anastomosis in a conventional CABG procedure, the surgeon sutures a proximal end of the graft vessel to the side of the aorta.
As this field of art has progressed over the last several years, new anastomotic methods have been developed and introduced in attempts to replace the suturing technique briefly described above. Many of these methods incorporate novel fasteners and fastener appliers. The requirement, however, to maintain intima-to-intima contact of the joined vessels remains just as important with these approaches. In fact it is often necessary, prior to joining the vessels, for the surgeon to evert (i.e., turn inside out) the end of at least one of the vessels over the end of a member such as a tube, ferrule, or bushing, etc., which is a component of the fastener or fastener applier. This exposes the intima of that vessel for presentation to the intima of the other vessel prior to fastening the vessels.
Although it is possible to evert larger vessels (e.g., over 5 mm in diameter) using standard forceps and graspers available in the operating room, such methods are slow and may result in excessive damage to the vessel everted. And, often the surgeon requires assistance in performing the eversion procedure. Furthermore, vessels smaller than 5 mm are very difficult, if not impossible, to evert using such methods.
There are several requirements for an effective vessel eversion device. As noted earlier, for proper healing, it is important not to injure the intima of either vessel during the eversion procedure. The eversion device also must be easy for the surgeon to use without assistance and require only a few steps to operate. The eversion device must be useful for a wide range of blood vessel sizes, particularly small vessels, e.g., having a diameter of about 2-3 mm or less. In addition, it is desirable for the eversion device to be useful on one end of a vessel, when the opposite end is already attached to the patient (e.g., at the distal anastomosis of a patient undergoing a CABG procedure). The eversion device should also allow for the proper length of everted tissue over the tube, bushing, or the like, depending on the requirements of the anastomosis device or method being used. Finally, it is desirable that the eversion device be low cost and yet operate reliably.
Accordingly, there is a need in this art for novel devices and methods for engaging and everting the end of a blood vessel (or other tubular body organ) over a member such as a tube, ferrule, bushing, or the like which can be used in a quick and effective manner without causing trauma to the vessel or the intima of the vessel (or tubular body organ).
It is an object of the present invention to provide novel eversion devices which are easy for the surgeon to use without assistance, and which efficiently and effectively engage blood vessels and evert the ends of blood vessels, including blood vessels having small or fine diameters.
A further object of the present invention is to provide novel eversion devices which engage blood vessels and evert the ends of blood vessels without causing trauma to the blood vessel or the intima of the blood vessels.
It is yet another object of the present invention to provide novel methods of engaging and everting blood vessels quickly and efficiently, while preventing or minimizing damage to the blood vessels and the intimas of the blood vessels.
It is still yet a further object of the present invention to provide a novel vessel eversion device and procedure for everting one end of a vessel having the other end already attached to another vessel.
Accordingly, an eversion instrument for everting an end of a vessel is disclosed. The instrument has a tubular member having an axial bore. The tubular member has a distal end and a proximal end, and a distal opening and a proximal opening in communication with the axial bore. An elastic membrane is sealably mounted on the distal end of the tubular member. The membrane has an inner side and an outer side. A plunger member is slidably mounted within said the axial bore of the tubular member. The plunger member has a distal end and a proximal end. There is a mandrel member that has a distal end and a proximal end. The proximal end of the mandrel member is mounted to the distal end of the plunger member, and the distal end of the mandrel member is in contact with the inner surface of the membrane. A spring is operationally engaged to the plunger for biasing the plunger in the distal direction and distending the membrane for insertion into an end of a vessel. A sleeve is slidably mounted over the membrane and at least a section of the tubular member. A proximal seal is mounted to the proximal end of the tubular member such that the proximal seal, the membrane and the axial bore define a sealed chamber having a volume. There is a pressure source mounted to the tubular member for pressurizing the sealed chamber to expand the membrane into an expanded configuration, and for depressurizing the sealed chamber to collapse the membrane into a collapsed configuration. The sleeve limits radial expansion of the membrane.
Yet another aspect of the present invention is a method of everting a vessel. An instrument is provided. The instrument has a tubular member having an axial bore. The tubular member has a distal end and a proximal end, and a distal opening and a proximal opening in communication with the axial bore. An elastic membrane is sealably mounted on the distal end of the tubular member. The membrane has an inner surface and an outer surface. A plunger member is slidably mounted within the axial bore of the tubular member. The plunger member has a distal end and a proximal end. A spring is operationally engaged to the plunger for biasing the plunger in the distal direction and for distending the membrane for insertion into an end of a vessel. There is a mandrel member having a distal end and a proximal end. The proximal end of the mandrel member is mounted to the distal end of the plunger member, and the distal end of the mandrel member in contact with the inner surface of the membrane. A sleeve is slidably mounted over the membrane and at east a section of the tubular member. A proximal seal is mounted to the proximal end of the tubular member such that the proximal seal, the membrane and the axial bore define a sealed chamber having a volume. A pressure source is mounted to the tubular member for pressurizing the sealed chamber to expand the membrane into an expanded configuration, and for depressurizing the sealed chamber to collapse said membrane into a collapsed configuration. The sleeve limits radial expansion of the membrane.
A tubular workpiece is provided. The tubular workpiece has an inner lumen, a proximal end, a distal end, and an inner surface and an outer surface. A vessel is provided. The vessel has a distal end, a proximal end, an inner lumen, and an inner surface and an outer surface. The vessel mounted in the lumen of the tubular workpiece;
The membrane is inserted into the lumen of the vessel while the instrument is in a depressurized mode such that the outer surface of the membrane is in contact with the inner surface of the vessel. The instrument is pressurized to an intermediate positive pressure mode. The sleeve is moved over the vessel and tubular member. The instrument is then pressurized to a full positive pressure mode, thereby everting the distal end of the vessel over the distal end of the tubular workpiece such that the outer surface of the distal end of the vessel is in contact with the outer surface to the distal end of the tubular workpiece. Finally, the instrument is depressurized to a negative pressure mode and removing the instrument from the vessel and tubular workpiece.
Yet another aspect of the present invention is a system for everting a vessel. The system is the combination of the above-described instrument and tubular workpiece.
These and other aspects and advantages of the present invention will become more apparent from the following description and accompanying drawings.